Algorithm-enabled partial-angular-scan configurations for dual-energy CT.

Area of Science:

• Medical Imaging
• Computed Tomography
• Image Reconstruction

Background:

• Dual-energy CT (DECT) offers enhanced material differentiation but is challenged by beam-hardening artifacts.
• Standard DECT often requires full-scan acquisitions, potentially increasing radiation dose and scan time.

Purpose of the Study:

• To investigate an optimization-based one-step method for DECT image reconstruction that corrects for nonlinear spectral response (beam hardening).
• To assess the feasibility of using this method with partial-angular-scan configurations (short- and half-scan) on standard CT scanners.
• To evaluate the potential of these partial-scan configurations in reducing radiation dose and scan time compared to full-scan DECT.

Main Methods:

• A nonconvex optimization program was used to directly reconstruct images from DECT data.
• Full-scan DECT data were acquired from numerical and physical phantoms.
• Short- and half-scan data were derived from full-scan data for comparative analysis.
• Image quality was assessed through visual inspection, profile plots, and quantitative analysis of material property estimation.

Main Results:

• The one-step method accurately reconstructed basis and monochromatic images from simulated and real DECT data.
• Monochromatic images from full-, short-, and half-scan configurations were visually comparable, with minor texture differences.
• Quantitative analyses showed that short- and half-scan configurations achieved results comparable to the full-scan configuration.

Conclusions:

• The one-step method effectively compensates for beam hardening in both full- and partial-angular-scan DECT.
• Partial-angular-scan configurations are feasible on standard CT scanners without additional hardware.
• These partial-scan methods demonstrate comparable performance to full-scan DECT, offering potential for reduced dose and scan time.